WSDL - Web Services Description Language. A WSDL file describes the legal requests that the web service accepts and responses that are generated as a result. It is a formalized description of the interface of the web service most often used by SOAP web services. See also Basic doubts in Web services
wsdd - Web Service Deployment Descriptor. An Axis specific web service deployment configuration file.
While using axis for Webservice we are writing only the wsdd config file and the wsdl file is already implemented in Axis. Is my understanding is right?